The present invention generally relates to a method for measuring atmospheric gases and a system for measuring atmospheric gases, and particularly, to methods for measuring atmospheric gases and a system for measuring atmospheric gases, by which, information such as an amount and a vertical distribution of gases considered to be responsible for temperature rise on earth, such as atmospheric ozone, carbon dioxide and infrared emission gases, is obtained and the accuracy of a temperature measurement in the conventional upper-air observation of the atmosphere is improved.
Currently, the measurement of a gas, for instance, ozone, contained in the atmosphere is carried out by using the Dobson spectrophotometer, which analyzes ozone by measuring ultraviolet rays from the sun on the earth, or using a ozone sonde which is capable of measuring the vertical distribution of ozone in the atmosphere. A meteorological satellite, by which ultraviolet rays from the sun may be observed, is also employed for measuring ozone.
Observation of carbon dioxide in air is carried out at many places on earth and also in upper-air region using airplanes.
Moreover, there is a method in which a white-painted thermistor sensor sensitive to carbon dioxide, clouds and water vapor but not sensitive to ozone radiation is used.
However, since the above mentioned Dobson spectrophotometer is not small enough to be set in a sonde, it has to be used on the ground, and hence the vertical distribution of ozone cannot be measured.
Also, there are a couple of problems associated with a temperature measurement using an ordinary temperature sensor exposed to air from an airplane or on the ground as follows:
a) since the white-painted thermistor sensor is sensitive to clouds, water, water vapor or carbon dioxide radiation as mentioned above, a large error may occur when there is a significant change in any of the above-mentioned factors; PA1 b) cloud particles may attach to the surface of the sensor and form blackish matter by which the sensor may become sensitive to ozone radiation; PA1 c) when an aluminium-deposited temperature sensor in world-wide use whose surface is coated with a thin layer of SiO is employed, water vapor tends to freeze on the surface and the surface becomes like a "clouded glass". In this state, since the SiO thin layer has a weak absorption in the ozone absorption band in nature, the sensor becomes sensitive to ozone radiation as well. This may cause a large error in the measurements.
If a water repellent is applied on the surface of the above-mentioned sensor in order to avoid this problem, although the freezing of water vapor can be stopped, an error due to the above-mentioned weak absorption in the ozone absorption band of the SiO thin layer still remains. Moreover, since a reflection effect by clouds is relatively increased due to the decreased warming effect by the ozone layer located above, a large error may occur in the measurements, especially in the troposphere.
The above mentioned errors caused by the white-painted thermistor sensor have been recently recognized by an analysis in which the results of measurements obtained when the white-painted thermistor sensor are used and those obtained when a bimetal sensor placed in a protective air flow duct are compared. It is now proposed to set a sensor which has sensitivity to infrared radiation and a senor which is not sensitive to infrared radiation in the same radio sonde and perform measurements of infrared radiation gases in the atmosphere by switching the sensors.